The present invention relates to a vise, and more particularly to a vertically pivotable one.
The vise is an important machine tool and conventionally includes as shown in FIGS. 1 and 2 a base 11 having two end side extensions 111 one of which is provided with a base line 111a, a body 12 pivotally mounted between side extensions 111 and having a longitudinal groove 121 and an angular scale 122, two adjusting triangles 13 respectively pivoted to two sides of base 11 and each of which has an elongate groove 131 through which a bolt 132 can pass to be threaded into one side of body 12, a movable seat 14 having a lower protrusion 141 which is slidably received in groove 121 and has a bottom screw hole 142, a limiting plate 15 through which a bolt 151 passes into screw hole 142, a screw rod 16 screwedly passing through an end piece 123 of body 12 to be rotatably but untranslatably fixed to movable seat 14 attaching thereto a jaw member 19, a driving handle 17 pivotally connected to screw rod 16 by a rivet 171, and another jaw member 18 attached to an opposite end piece 124 of body 12 so that body 12 and base 11 can have an included angle variable between 0 and 90 degrees for angularly working.
Such vise suffers from the following disadvantages:
(1) Since screw rod 16 is centrally connected to movable seat 14, as shown in FIG. 3, the vise 10 can only clamp thereon a small part of a work piece 1 to form a so-called "trumpet mouth" between jaw members 18 and 19 if workpiece 1 is relatively short and needs to be sidely clamped for working so that the clamping effect is not good to badly affect the working accuracy or even workpiece 1 will escape from vise 10.
(2) Seat 14 is slidably guided in groove 121 by limiting plate 15 which results in that if vise 10 is fixed on a milling machine or the like, the vibration caused easily gets bolt 151 loosened which in turn results in that seat 14 can no longer be smoothly guided in groove 121 and that workpiece 1 is slightly vertically displaceable to badly influence the working accuracy.
(3) If vise 10 is to act as an angle vice, the force imparted by the working machine on body 12 is primarily taken by adjusting triangles 13 which always are of iron plates being not very thick and will be flexed or deformed upon executing a heavy cutting.